№6 2021
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1
The development of industrial production in the modern world cannot do without the use of new technologies. This article discusses various methods for the additive manufacturing of magnesium alloy parts. There are several alternative methods for producing parts, such as selective laser fusion, direct laser deposition and arc welding. Depending on the additive manufacturing method, finished parts will differ in structure, phase composition and mechanical properties. The article presents a comparison of traditional and additive manufacturing methods for parts.
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2
The article provides an overview of studies on the influence of HIP on the density, roughness and mechanical properties of cast aluminum alloys. As a result of HIP, the density of the alloy, its ductility, and cyclic characteristics increase, and the scatter of mechanical properties determined during tensile and long-term strength tests decreases. The use of HIP increases the yield of good casting due to the reduction of rejects due to unacceptable porosity detected during х-ray inspection. Thus, the casting acquires a homogeneous, completely dense structure.
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3
The article provides an overview of the literature in the field of composite materials (CM) based on metal matrices reinforced with carbon fibers. The main structural, physical and mechanical properties and morphology of such CMS are briefly described. The structure and properties of new CMS from multilayer metal-intermetallic multilayer laminates reinforced with carbon and ceramic fibers are also presented. Application of the method of ultrasonic consolidation for the manufacture of multilayer fibrous CMs based on metal-intermetallic laminates provides high adhesion of fibers with an intermetallic layer.
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4
Presents a literature review in the field of methods for strengthening titanium and its alloys by introducing various refractory particles into the matrix. The main problematic issues related to the chemical nature of refractory particles and titanium alloys that arise during hardening are briefly described. The main structural, physical and mechanical properties and morphology of such metal composite materials are described. The dependence of the influence of various refractory particles and their amount, as well as the effect of heat treatment on the physical and mechanical properties of microns based on titanium alloys, is presented.
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5
The main technological factors when using ATL and AFP technologies are material temperature, laying speed, rolling pressure and no deviation from the required laying trajectory. The article discusses the influence of technological factors on some characteristics of polymer composite materials. The optimum laying temperature should provide the required adhesion. The rate of laying should provide heating of the material without its technological properties. The rolling pressure during laying should ensure optimal porosity and thickness of the material.
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6
Various methods of applying lubricants to the surface of ceramic oxide fibers after firing have been tested. It is shown that the contactless method of applying the lubricant reduces the breakage of fibers during rewinding. The selection and testing of lubricant compositions that improve technological properties during textile processing operations have been carried out. Comparative tests for breaking load and flexibility of multifilament yarns oiled with different compositions have been carried out. Rigidity, adhesion and breakage during unwinding from the package are assessed.
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7
Presents the results of a study of the effect of the final curing temperatures on the complex of properties of the developed epoxy binder grade VSE-65 and glass-fiber-reinforced plastic based on it. It was found that with a decrease in the final curing temperature, the residual heat effect increases and, in turn, a decrease in the conversion of epoxy groups occurs. Presents the results of a comparative analysis of VKG-6 glass-carbon plastic samples prepared by vacuum infusion and pressure impregnation. Based on the results of the analysis, it has been established that the technologies make it possible to realize the required level of physical and mechanical properties.
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8
In this paper, the main properties of glass fiber laminates – dielectric composite materials for printed circuit boards are considered: glass transition temperature, temperature coefficient of linear expansion, ultimate strength in bending, water resistance. The influence of climatic influences (increased ambient temperature, low ambient temperature, increased air humidity, the effect of temperature changes, the effect of salt fog) on the dielectric constant of glass fiber laminates has been evaluated.
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9
A review of modern scientific publications in the field of methods for preparing the surface of aluminum alloys for electroplating is presented. It is shown that the most widely used methods of preparation are: zinc treatment, high-porosity anodic oxidation and immersion nickel plating. A number of combined methods for preparing the surface of aluminum alloys for electroplating are given. Methods of direct application of electroplating coatings on aluminum and its alloys without the use of a sublayer, both by electrolytic and chemical methods, are considered.
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10Part 1
The article provides an overview of the scientific and technical literature in the field of the formation of silicon carbide coatings by chemical vapor deposition (CVD). CVD is a complex process, approaches to which vary depending on the tasks being solved. Depending on the technological parameters, the initial reagents, the substrate for deposition, the type and design of the CVD reactors, it is possible to achieve both the deposition of pure silicon carbide and the co-deposition of silicon and/or carbon.
In the first part of the article, attention is paid to the study of CVD from the point of view of the mechanisms of chemical reactions, the design of the deposition apparatus, the substrates for deposition.
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11
In this work, we consider the issues of determining the chemical composition of heat-resistant nickel alloys at various stages of the production of semi-finished products and finished products from them using additive technologies. An overview of the existing analytical control system of the laboratory of the VIAM Testing Center, in which the elemental composition of metallurgical materials is determined, is given. Analytical control was carried out at different stages of additive manufacturing in the manufacture of synthesized parts from VKNA-1VR-VI and VZhL12U-VI alloys.
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12
The article considers the results of the study of the uneven distribution of the strength properties of a rigid high-temperature fibrous heat-protective material over the volume of the block. The article presents a comparative study of the uneven strength of two materials that differ in the method of introducing the binder. A conclusion is proposed about the mechanism of the occurrence of unevenness of the strength properties of a rigid fibrous thermal insulation material when a soluble binder is introduced into the material by the strait method. The absence of such a mechanism is shown for materials obtained using a solid-phase binder introduced into the molding hydraulic mass.
